Cocaine and its metabolites (benzoylecgonine and methylecgonine) were assayed in biological fluids and organs the same day, using both techniques. The TDx Cocaine Metabolite Assay measured only benzoylecgonine in biological samples, and the cross reactivity with cocaine and methylecgonine was negligible. The results indicate agreement in the benzoylecgonine concentrations measured by both methods and thus demonstrate the ability to use the TDx analyzer to assay benzoylecgonine in other samples than those proposed by the manufacturer. A slightly positive bias in the TDx results relative to the GC/MS for benzoylecgonine was found. This can be explained by cross reactivity with cocaine and methlecgonine present in the sample; however, for practical purposes the difference in results was negligible. Dilution with saline was necessary to bring values within the range of the calibration concentrations and to decrease the blank intensity of the bile and the liver, probably because of the natural fluorescence of the bile pigments and the chromophores in the liver matrices. Overall, the findings show the merits of the Abbott TDx in screening rapidly (15 minutes) fluids and organs for cocaine, using only 50 ml of sample. 1 table and 8 references